The present invention relates to internally illuminated outdoor signs, and particularly to a sign system incorporating a scroll module adapted to display a message selected from a plurality of messages on a message web. While directed to an internally illuminated sign, the scrolling apparatus used in the display module can be used without the internal illumination for general message display and advertising purposes.
The use of message scrolls, wherein a message web is wound between two cylinders, has been known since ancient scribes recorded the events of their times. In more modern times, the scroll system has been adapted for mechanical operation in order to display messages contained thereon. For example, U.S. Pat. No. 1,024,044, issued Apr. 23, 1912 to Tucker, discloses a scroll assembly having a message web wound on a pair of message rollers that are driven by a gear system with the message web being trained across two display stations. U.S. Pat. No. 1,547,495, issued July 28, 1925 to Galley, discloses an advertising apparatus incorporating three message rollers with one message roller receiving message webs from each of the other two rollers. In this system, a drive cord is provided and an idler wheel bears against the cord to maintain tension on the roller assembly.
In U.S. Pat. No. 3,616,554, issued Nov. 2, 1971 to Finger et al, a pair of independent motors operate a respective message rollers so that a message web may be trained between a support surface and viewing face. U.S. Pat. No. 4,205,801, issued June 3, 1980 to Decaux, discloses a band winding device wherein a message band is wound on a pair of spaced apart, parallel rollers. The rollers are driven by an endless chain and sprocket drive with a drive motor directly engaging the chain. To compensate for changes in radial dimensions as the band is wound from one roller to another, the drive chain has two looped portions with each looped portion being trained around a pulley mounted on a moveable carriage. A weight is suspended around a third pulley on the moveable carriage to apply a substantially constant gravitational force on the drive chain.
Many of the prior art scrolling assemblies have, however, been fairly complicated in structure and expensive to manufacture and maintain. Due to the complexity of the assemblies, especially where gear driven systems are provided, these units may experience a relatively high rate of breakdown which decreases their usefulness, especially in locations that are difficult to access. A problem has been experienced by many prior art assemblies in that the message web tends to drift laterally of the view opening; also, the message web may lose its tension and sag. Further, due to the internal structure of these devices, the prior art scroll assemblies are difficult to illuminate interiorly so that illumination of the message band requires an external light source which can diminish the practicality of the systems.
Accordingly, there is a need for a relatively low maintenance scroll apparatus that is simple in construction yet reliable in operation. There is a further need for such a scroll apparatus module that may be internally illuminated and which may be used along or in combination with other modules to form a display sign that is particularly adapted to be used at locations having relatively difficult access.